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Ⅲ. Explanation of Molding
The robot has many plastic parts for its body and the controller. There are many plastic
products around you also. When you compare the same plastic parts from the same products,
you can see they have exactly the same form. Otherwise, the parts could not fit with the
matching parts or the products would have uneven quality. Then, how are these plastic parts
are made to be same? The technique called “molding” is used to make the plastic parts.
There are many ways to mold the plastic.
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Injection molding
Injection molding needs more than two pieces of metallic molds. The mold is processed with
tools for cutting, holing and making posts to shape an exactly opposite surface to the plastic
part, which will be molded.
When the molds are fitted together, there will be opening inside made from the above carving
process, and the melted plastic will be injected there. The plastic will be taken out from the
molds after it cools down and becomes solid. In this way, plastic parts are produced to have
the same shape.
It is similar to making waffles. The mold is a waffle iron and the melted plastic is batter, so that
the completed plastic parts will be waffles.
The injection molding is used to make the plastic with a rather complicated shape, such as the
parts used for this robot.
1. Molding Procedure
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Various ways of molding
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Injection molding
The heaters will melt
the plastic.
Screw
Pressing out the melted plastic.
Hopper
Small pieces of plastic are inside.
Mold
The melted plastic will be injected
Motor